Definitions A-D
Acoustic Neuroma
A benign tumor arising from Schwann cells of the vestibular division
of the eighth cranial nerve within the internal auditory canal. Also
called vestibular schwannomas, these growths are progressively enlarging
and commonly lead to progressive hearing loss, headache, ringing in
the ear (tinnitus) and balance problems. Treatment options include surgical
resection, stereotactic radiosurgery or fractionated radiation therapy.
They may be unilateral or bilateral.
Arteriovenous Malformations (AVM)
A spectrum of congenital (developmental) blood vessel malformations.
An AVM occurs when brain or spinal cord arteries attach directly to
veins without the blood passing through the capillary network. AVM's
can cause bleeding within the nervous system (a kind of stroke), or
progressive neurologic deficits, headaches or seizures. They occur in
a variety of brain locations, sizes and shapes. Treatment can consist
of observation, surgical resection, embolization or radiosurgery. (See
also Spinal Cord Arteriovenous Malformation.)
Astrocytoma
A nervous system tumor that grows from astrocytes (astrocytomas are
a type of glial cell, glial cells are the supporting cells of the nervous
system). They can occur in children and young adults and sometimes in
older people. Astrocytomas can sometimes become large before causing
symptoms. A diagnosis is made either after surgical resection or with
a guided (stereotactic) biopsy. Treatment can consist of surgical excision,
radiation therapy or chemotherapy. Some patients with minimal symptoms
may be observed with serial imaging studies.
Ataxia
An abnormality of coordination -- particularly affects walking; gait
is typically very unsteady.
Athetosis
Movement disorder indicated by slow, writhing motions of the fingers
and hands. Occurs in approximately 5% of people with cerebral palsy.
Athetosis was used commonly a few years ago, but now, many of the people
who were previously diagnosed as having athetosis are considered to
have dystonia. We believe the two disorders are different, in that athetosis
affects muscles of the fingers, hands, and around the mouth, causing
slow, twisting, writhing motions that are more continuous than dystonic
movements.
Atypical Trigeminal Neuralgia
Pain syndrome with characteristics of typical trigeminal neuralgia as
well as characteristics of other facial pain syndromes.
Brachial Plexus
The network of spinal nerves (from the lower cervical spine and upper
dorsal spine) that innervate the arm, forearm and hand. Located in the
neck-shoulder region
Brain Contusion
An injury (bruise) to the brain. This usually occurs in the setting
of a head injury but can occur after other kinds of trauma. Contusions
sometimes lead to focal neurologic deficit. They can be single or multiple.
If the bruise enlarges, a focal hemorrhage can lead to a decline of
the patient and require surgical removal.
Brain Metastasis
A tumor, which spreads from one part of the body to another. The most
common metastatic tumors in the brain come from lung cancer, breast
cancer, skin cancer (melanoma), kidney cancer (renal), or gastrointestinal
tract tumors. They can cause seizures, headaches or neurologic deficits.
Treatment consists of either tumor irradiation (stereotactic radiosurgery
or whole brain radiation therapy), surgical resection, or corticosteroid
therapy, alone or in combination.
Brain Tumor
A tumor or neoplasm refers to a "new growth" of cells that
already exist in a certain part of the body. Many different tumors can
occur in the nervous system. They often cause headaches, seizures or
neurological deficits. Tumors can be both benign or malignant. Malignant
tumors are referred to as cancers. Tumor treatments can consist of surgical
resection or biopsy, radiation approaches or drug treatment approaches
(chemotherapy). Other tumors can be treated with modification of the
body's own immune system (immunotherapy).
Bypass
Blood vessel procedure where blood is shunted from one blood vessel
to another without passing through a diseased segment. This is usually
performed if a certain portion of the brains blood supply is significantly
compromised. A bypass allows a higher volume of blood to enter the brain
in an attempt to prevent a stroke. The most common bypass is an EC-IC
(extracranial - intracranial) bypass.
Carotid Endarterectomy
Procedure where an artery is opened and a portion of atherosclerotic
disease (plaque) is removed. Arthrosclerosis refers to the "hardening
of the arteries" that can occur with advanced age. Patients particularly
prone to this are those with risk factors including high blood pressure,
smoking, hypercholesterolemia, or family history. Patients who have
a carotid endarterectomy usually have significant narrowing of the carotid
artery (one of the main arteries supplying the brain with blood). Many
patients have symptoms from arterial narrowing such as transient ischemic
attacks or stroke.
Carotid Stenosis
Narrowing of the carotid artery caused by atherosclerosis. A plaque
forms within the artery leading to it's narrowing (stenosis). The stenosis
can be opened by removal of the plaque (endarterectomy) or distention
of the plaque (angioplasty).
Carpal Tunnel
Compression of the median nerve at the wrist. This causes numbness in
the hand, thumb, and fingers.